Find out the basic strength order

see in this image,nitrogen inversion is not possible in the bicyclo compound but in triethylamine due to rapid nitrogen inversion the lone pair is not available for donation easily...

Bridged N will be more basic

See this. Due to pyramidal inversion lone pair is not static

Since NR3 will show pyramidal inversion show it will be less basic.

Bridged N will not show such inversion.

check the lone pairs of electrons of nitrogen is available on which hybridized orbital...if in Sp3 it is more basic than sp2 than sp...also bridged nitrogen basicity will more

hope this will help you shraddha🙏😊